Interior wall framing

Hello,

I have a garage with 12' walls, and I want to add an insulated partition wall to divide the space. The lumber I have is 2x6 x12'. The bottom of the ceiling joists are actually at 12'8" because the foundation wall comes up 8" above the floor.

So with 1 bottom & two top plates I would be missing 3 1/2" if I use these 2x6s. Would it be OK to use 2x4s on edge to fill in this space? I'd prefer not to have to order 14 foot lengths and cut them.

Interior wall framing

Just stack two more top plates on there. A couple lengths of plate stock is a lot cheaper than all those new studs you'd otherwise have to buy. Plus it'll be a lot more solid connection to the joists above than you'd get with a 2x on edge.